Aquaculture is a known technique consisting of raising aquatic animals such as snails, fish, prawns and lobsters in a confined and limited tank. In addition to dispensing sufficient amounts of food, known aquaculture systems must use electrically powered heating devices to keep the aquatic environment at the right temperature, and electrically powered aeration devices to provide it with sufficient oxygen to sustain animal life. In addition, depending on the type of animal, electrical pumps may have to be provided to generate a current of the water.
Hydroponic culture is a known technique consisting of cultivating vegetables and herbs in water instead of a soil-based substrate. The water must be provided with sufficient nutrients to sustain plant life.